The GNU subunit of PNG kinase, the developmental regulator of mRNA translation, binds BIC-C to localize to RNP granules.

Control of mRNA translation is a key mechanism by which the differentiated oocyte transitions to a totipotent embryo. In , the PNG kinase complex regulates maternal mRNA translation at the oocyte-to-embryo transition. We previously showed that the GNU activating subunit is crucial in regulating PNG and timing its activity to the window between egg activation and early embryogenesis (Hara et al.

Identification of New Regulators of the Oocyte-to-Embryo Transition in .

At the oocyte-to-embryo transition the highly differentiated oocyte arrested in meiosis becomes a totipotent embryo capable of embryogenesis. Oocyte maturation (release of the prophase I primary arrest) and egg activation (release from the secondary meiotic arrest and the trigger for the oocyte-to-embryo transition) serve as prerequisites for this transition, both events being controlled posttranscriptionally. Recently, we obtained a comprehensive list of proteins whose levels are developmentally regulated during these events via a high-throughput quantitative proteomic analysis of oocyte maturation and egg activation.

Early genome activation in is extensive with an initial tendency for aborted transcripts and retained introns.

Control of metazoan embryogenesis shifts from maternal to zygotic gene products as the zygotic genome becomes transcriptionally activated. In , zygotic genome activation (ZGA) has been thought to occur in two phases, starting with a minor wave, in which a small number of genes become expressed, and progressing to the major wave, in which many more genes are activated. However, technical challenges have hampered the identification of early transcripts or obscured the onset of their transcription.

Dynamic changes in ORC localization and replication fork progression during tissue differentiation.

Background: Genomic regions repressed for DNA replication, resulting in either delayed replication in S phase or underreplication in polyploid cells, are thought to be controlled by inhibition of replication origin activation. Studies in Drosophila polytene cells, however, raised the possibility that impeding replication fork progression also plays a major role.

Results: We exploited genomic regions underreplicated (URs) with tissue specificity in Drosophila polytene cells to analyze mechanisms of replication repression.

Dynamic redox balance directs the oocyte-to-embryo transition via developmentally controlled reactive cysteine changes.

The metabolic and redox state changes during the transition from an arrested oocyte to a totipotent embryo remain uncharacterized. Here, we applied state-of-the-art, integrated methodologies to dissect these changes in We demonstrate that early embryos have a more oxidized state than mature oocytes. We identified specific alterations in reactive cysteines at a proteome-wide scale as a result of this metabolic and developmental transition.